Decepticons of the Covenant
by phoenixforce50
Summary: The Covenant comes across a strange alien ship in an undiscovered sector. Little do they know of the evil they will unleash inside.
1. Chapter 1

"Sir, we've come across the remains of some kind of ship, we don't know what its origin is but it certainly isn't one of ours, it's not human and it's not a sacred artefact. Orders?"

The Sangheili commander turned to the screen the Kig-yar was seated at. How boring this was! He wished dearly that he could be out there, spilling the blood of his enemies on the glory that was the battlefield but no, the Prophets had ordered him for reconnaissance duty into this unknown area of space.

"How big is it?" he asked

"It's about as big as our flagship, slightly larger." replied the Kig-yar

"Okay then, send a wreckage team to examine it, it might hold useful information about any new enemies we may encounter here."

"Yes sir," the Kig-yar reached for the PA system controls "wreckage team to the hangar bay now."

Down in the recreation hall, the recipients heard their call.

"Hear that? That's us." said a small Grunt to his friend next to him

"Aw, I was hoping to have a bit more time in the breathing room, I guess it will have to wait." replied the aforementioned friend.

Both the Grunts walked down to the hanger were two Phantoms were waiting. The rest of the wreckage team was already there, putting on their zero-gravity gear. The Grunts looked at the rest of the team: there were two Sangheili, the leaders of the operation, four Kig-yar, on account of their excellent eyesight, one Huragok, for examining what they found and three more Grunts like themselves talking in a group. The Sangheili were having a little trouble getting the team in order; they had been in this sector for three weeks and nothing had come up, the fact that something had been found and that they were the ones to see it first sparked much excitement among the ranks. Finally, the two Sangheili managed to get everyone's attention.

"Alright," said the slightly taller one "we've found what appears to be a ship of unknown origin, you know what to do: go in there, find anything of interest and bring it back here intact. Those of you with specific tasks, do them to the best of your ability,"

_As if we needed to be told _thought the Sangheili on his left

"now, get in the Phantom. We leave immediately." The two Sangheili simultaneously turned and got in, one in the pilot's seat, the other at the head of the passenger bay. The rest of the group followed, excited chattering amongst them.

As the Phantoms approached the alien ship, the murmurs between them ceased, the big moment was about to happen. They were going to be the first to see a new kind of technology! Who knew what else would be inside? A new weapon? Information? A new race of creatures that might join the Covenant?

Inside the alien ship, something stirred something old and powerful. A faint alarm was ringing: proximity alert. Something was coming, but what? It couldn't be backup; they didn't get time to make a distress call. They were attacked so quickly that they only realised who it was after their ship was destroyed. The ancient being slowly got to its groaning feet, stood at its full height and walked to the nearest control panel. The cracked screen hissed with static as the external display came into focus; something about as big as he was coming towards them, seemingly with the intention to dock, it was smooth, with rounded edges and fins on the back and purple, very purple. It frowned, which was difficult to do because of the aged joints, but then grinned with a renewed purpose.

"Someone is foolish enough to wake me are they?" the towering being said to himself "well then, I guess I had better not keep my guests waiting."

It tried flexing its body in the way that was unique to his species but could not

"Hrm," it said "I'm getting old. I hope these guests bring gifts for me." It walked down to the sealed off area where the hole in the ship that the new craft was heading for was. It crouched low beside the hole and waited.

Inside the Phantom, the Sangheili directed it into the wrecked armoury, avoiding the jagged pieces of metal on the edge of the hole. As it entered, he had a sudden pang of fear which disappeared as quickly as it had come.

_Must be nothing _he thought to himself. The room was huge, obviously built for a people much taller than him, filled with strange devices that did who-knows-what. As he landed, he was not aware of the beam of light scanning the Phantom right next to him. As soon as the last member of the wreckage team was off the Phantom, it exploded, sending all of them flying in different directions, fortunately none of them were thrown into space but they were all dazed. When they turned to where the Phantom used to be, the found it was still there, only in flight, with its plasma cannon pointed straight at them. The Sangheili were he first to go, followed by the Kig-yar and then the Grunts, who had wisely chosen to flee but could not escape the marksmanship of the supposedly empty Phantom. It thought to itself as it flew out the hole towards the other fleet that had appeared.

"Wreckage team, you're back early, did you find something already?" asked a reptilian voice through the comlink.

"Wreckage team? Please respond." said the voice again.

"The wreckage team found something alright, but I'm not the wreckage team. I am…Megatron!" yelled Megatron as he flew towards the ship.


	2. Chapter 2

**Chapter 2**

Explosions rocked the ship, the Sangheili commander ran through what was left of his flagship. The single thought: "How could one Phantom destroy a whole fleet?" kept running through his mind. How did this happen? Oh yes, that's how: after hearing the voice that was certainly not that of the Sangheili leading the wreckage team, he ordered that the hangar doors be closed to prevent the possibly hostile ship from boarding. After the Phantom had realized that it wasn't going to get in that way, it flew around and started attacking the other ships in the fleet. This wouldn't have been so bad, except the Phantom was much more agile than he remembered it to be, and its firepower was much greater that standard plasma cannons. The rogue Phantom had decimated the fleet by avoiding their fire and aiming at the vital areas. After destroying most of the fleet and incapacitating the rest, the Phantom set its sights on the flagship but instead of destroying it, it did something extraordinary: as it neared the hangar doors, it began to fall apart symmetrically, when all of a sudden, it rolled and flipped and extended in all directions to become humanoid, although made of metal and huge. Its arms became weapons he had not seen before and blasted away at the hangar doors, where most of the troops inside were killed by the giant's plasma fire. Some of them tried to return fire but it could not penetrate the invisible field of energy surrounding the giant. For some reason, the giant tried to keep all their vehicles intact.

"Aah!" came a scream from down the corridor followed by an explosion, snapping the Sangheili commander out of his flashback. He ran towards where the escape pods were. He jumped in and launched it as another explosion, closer this time, rocked the ship. As the Sangheili flew away, he breathed a sigh of relief which was interrupted by a bone-jarring crash. The pod had stopped; the side of the pod contracted dangerously and was _pulled back into _the ship. The door was torn off and a large metal face stared at him.

"Tell me about your world." said the face

"I will never reveal anything about the Covenant to something like you!" shouted the Sangheili defiantly.

"That was a bad choice," replied the face "you will give me information, whether you want to or not."

"Aargh!" screamed the Sangheili commander

"Why are you not so forthcoming? It is inevitable. I already know where your home world is so just tell me about everything else!" roared Megatron, clearly angry at the Sangheili's loyalty to his mysterious Covenant.

"Very well," began Megatron, calming down "if you will not tell me anything about it, I will have to find out for myself. But first, I think I should introduce you to my friends."

Megatron walked over to the door and left. The Sangheili commander struggled against his restraints but to no avail. Curse this metal giant! He's going to attack the Covenant home world and judging by how easily he defeated our fleet, if there's more of them then the Covenant is doomed.

Megatron had brought in some vehicles from the hangar bay of the flagship. He'd brought back a Seraph, a Revenant, a Brute Prowler, and a Wraith. Down in the stasis chamber, Megatron had brought his followers out of their pods and given them new forms. Afterwards, they all walked back to the broken control room.

"Bonecrusher, it seems that our guest does not want to talk, would you kindly make him more, eloquent."

Bonecrusher looked at the puny writhing life-form beneath him and smiled with glee, although it was a bit hard to smile with a face like his. Bonecrusher extended every instrument of fear he had in his arsenal and held them gloatingly above the Sangheili's face. The Sangheili stared up at the multitude of assorted blades, probes and Forerunners-knows-what looming over him and decided to give in. Even if those who were faithful went on the great journey, he would be shamed for letting this strange enemy beat him.


	3. Chapter 3

**Chapter 3**

"Prophet of Truth, we have lost all contact with the advance fleet in the new sector that you ordered be explored."

The Prophet of Truth thought for a moment. His thoughts went along the lines of: _Hm, should I bother doing something about this mishap? I feel _so_ bored it's just not worth it._

"Uh, what are we going to do about the lost fleet?"

"Hm? Oh sorry. Yes I suppose that you might as well send a search team to find what's left of them."

"Yes, holy one. Although I do wonder what could have taken out an entire one of our fleets."

"Whatever, just find out what happened." Replied the Prophet

The Sangheili knelt before him and exited.

_Well, maybe something interesting _will_ happen today after all. _thought the Prophet as he watched the Sangheili leave.

"So, have you found the location of their home world yet Starscream?" asked Megatron from the doorway

"Not yet my lord, there is much data to sort through and I am only partially versed in data analysis." replied Starscream, attempting to sound humble.

"Get on with it then." Megatron was about to walk out the door when Starscream made a surprised sound

"What is it? Have you found it?"

"No, but I have found something else: the identity of the Covenant's greatest enemy."

"And who might that be?"

"The humans."

Megatron thought to himself.

_The Humans? It's been long since I heard of them. I wonder what has become of those snivelling pests._

"Apparently, the Covenant sees them as blasphemy to their religion, which involves beings called Forerunners who apparently became gods by traversing some kind of Great Journey."

"How can one start this Journey?"

"There are the locations of a few Sacred Objects called Halos and once they've been activated, the Great Journey will begin for those who believe."

"Ba, mystic nonsense. Keep searching."

Megatron walked out the door towards where the others where situated.

"Barricade, how do you like your new body?" asked Megatron

"It's alright, I suppose. Not sure about the light plasma mortar it has, though. A little inaccurate but I think I'll get the hang of it." replied Barricade

"Good, keep practicing on those little things that keep showing up every now and then."

Megatron went through the ship, checking each of their capabilities as he passed. He was not normally this caring but since none of them were used to these kinds of weapons and vehicles he thought that he should make sure he knew the full extent of each and every one of his troops.


	4. Chapter 4

**Chapter 4**

Jun rode in the Warthog towards the base camp. He had had a very tiring day going back and forward from place to place, wiping out the last traces of Covenant stragglers after they kicked them off of Reach. It had taken many years but they had finally taken back their planet. Jun was tired but happy. It felt so good to be home but he missed the rest of NOBLE team. He was once again reminded of how he was forced to abandon them on ONI's orders. There was a report of a new ship coming in but it seemed slightly damaged so it wouldn't be much of a problem. For the last time that day, Jun put his helmet back on, picked up his rifle, checked it over and clambered into the waiting Pelican. The Pelican took off and headed in the direction of the ship's landing zone. They arrived without any delay or Covenant encounters. Maybe they thought that the new ship had reinforcements and would fight the humans. The ship lowered its gravity lift. On it were three vehicles. There was a Wraith, a Brute Prowler and a Revenant.

"Uh sir, thermals clean, those vehicles are unmanned." said a marine next to Jun

"Stay low. Even if they are unmanned, they may be still dangerous." replied Jun

The vehicles on the lift began to move.

"Sir, enemy tangos are mobilising."

"Heavy artillery, move in and eliminate them quickly. Don't want too many casualties if we can afford it." ordered Jun

Multiple Rhino laser tanks escorted by Warthogs moved towards the gravity lift. The Rhinos stopped just beyond the hill and took aim at the apparently empty vehicles.

"Steady," said Jun "wait for them to make the first move." Suddenly, the Revenant dashed forward, firing at the marines who were closest to the lift. The marines tried to scatter but the Revenant had remarkable accuracy and those that it did not hit with its plasma mortar it splattered while boosting. By this point, the Wraith and Prowler had also moved off the lift and started firing on the marines and Spartans. Jun yelled into his comlink

"Fire! Fire now!"

The Rhinos, who were already settled for firing, loosed their high-power lasers on the Covenant vehicles, who were all so agile that they missed completely. The Wraith responded in kind and hit one of the Rhinos, crippling it and causing some splash damage to the others. The Rhinos attempted a hasty retreat and the marines followed suite. Jun couldn't believe it. Howe could three vehicles have done so much damage and force them to retreat? Also, how could they have been unmanned? Was it some kind of new Covenant technology? Mankind had tried to do something similar many years ago but they focussed on aircraft, not land vehicles. When Jun got back to base, he was intrigued with the concept of vehicles that could pilot themselves and decided to cross-reference them. He went to a console and typed in: 'self-piloting,' vehicle,' 'military.' The results that came up were hardly anything new but then he remembered a little trick Kat taught him. After making sure no-one was watching, he fiddled with some of the passcodes he had available to him. When he thought that he had it right, he tried re-inserting the same key-words. This time, the results were more satisfying but all the more confusing. There were multiple files named 'NEST,' 'sector 7,' and some others like 'Samuel Whitwiky,' 'Optimus Prime,' 'Bumblebee,' 'Megatron,' 'Transformers' and 'Alspark.' Jun couldn't make heads or tails of it. Who or what were all these things that they mentioned? He opened up the first file. A red box appeared on the screen. It read: you do not have sufficient rank to view this file. Jun frowned. Something was going on, something big, but no-one was going to tell him. It was time to start taking matters into his own hands.


	5. Chapter 5

**Chapter 5**

Somewhere, an alarm sounded.

"Optimus, we've been spotted. What shall we do?" said a gravelly voice from the shadows.

Optimus Prime was getting old, very old. It was a miracle that he and the few surviving Autobots had survived this long without being spotted or destroyed. That last crushing blow against Megatron when they had attacked him while he was hidden in that convoy all those years back was a huge success; the humans had not seen any Decepticons for centuries. But still, as was their solemn duty, the Autobots watched over the young race, in secret, hiding in plain sight. And although the humans had evolved their technology to the point that it was almost unrecognisable from what Optimus was used to, it still provided able forms for them to inhabit.

"We should analyse the situation. No-one is going to suspect us, the idea itself is still radical to the humans. They would not look directly for us unless they had exact information. It must have been a key-word search that triggered the sensors."

"But the only key-words that the sensors are programmed to look for are: unmanned, transform/-ing, vehicles, invisible force field, our names and the names of human institutes involved with us like NEST. Someone must have gotten close and put a few of them in a search." Replied a slightly more relaxed voice from somewhere else

Optimus thought for a second.

"Check on what's happening, military-wise. I hope it's not what I think it is." Said Optimus

"Ok, it says that humankind is at war with several alien races known as the Covenant, and most recently, on the former human planet Reach, the last group of Covenant were apparently made up of three unmanned vehicles which quickly and efficiently disposed of the human forces, does that sound like them?" reported the more relaxed voice.

"The way the fought, yes, but that doesn't mean it's them, but that combined with the fact that they were unmanned confirms my suspicion. We need to leave, now. Autobots, roll out!"

And with that, the Autobots opened the door of the hangar that was left for them, hidden in an old military base and began to choose suitable forms to inhabit. Soon after, a Pelican, Scorpion, Warthog, Gremlin and a Mongoose were seen leaving the base, heading towards the shipyards .The five Autobots stowed away on the next ship to Reach, easily blending in with the other vehicles in the hangar bay.

"Optimus, if it is the Decepticons, what do we do?" asked the gravelly voice over a closed channel known only to the Autobots

"We do what we always do Ironhide, we fight." replied Optimus, settling for the journey.


	6. Chapter 6

Author's Note: Apologies for the lengthy conversation, but i will make up for it with a movie-style battle scene next time.

**Chapter 6**

When the Autobots landed, they did not expect to see what they did; they saw a world, burning, no buildings stood, crashed ships were everywhere, both human and Covenant. The Autobots, still in vehicle mode, stalled for a few seconds before pulling themselves together. The same thoughts were still going through all of their minds: what kind of enemy came through this place? They must surely be formidable to do this much against the humans. Jazz was a bit worried, as he had a very close call with Megatron last time they met in battle. The Autobots moved onwards towards the newly established base, unloaded their crew and cargo and sat there, waiting for the right moment to reveal themselves.

Elsewhere, Jun was doing the thing he hated most; paperwork.

"Ok, just these last few forms and we can go and have our break." Said a marine cheerfully

"Oh my god, you've got to be kidding, right?" replied Jun "How can you enjoy something like this?"

The marine looked at Jun and scowled, Jun glared back at him and the marine went back to work.

Jun sighed. "It's people like this who should be working in an office, not on the battlefield." Said Jun quietly to himself. He had completely put the previous incident with the strange vehicles out of his mind. It was declared an enigma and nothing was to be done about it. It was common knowledge the enemy had set up a base there and that area was now restricted. But deep in his mind he was still wondering about what it was that attacked them.

The Autobots had managed to isolate Commander Holland who was driving Bumblebee along a secure route. Bumblebee made Holland lose control and swerve into a ditch. As Holland was getting up, Bumblebee transformed and the rest of the Autobots revealed themselves. Holland looked up and saw five giant robots standing over him. He was at a loss for words, then one spoke:

"Are you Commander Holland of the United Nations Space Command?"

Holland nodded

"My name is Optimus Prime, we are here to assist you in your fight against the Decepticons, the unmanned vehicles who caused the destruction of the advance squad in sector 56 at 1634 local time."

"An- and why do you need me?"

"You are a figure of authority here, we are sworn to assist the humans when their world is threatened, and believe me, the Decepticons are a large threat to your survival." Interjected Jazz

"O-kay, so what do you want me to do about it?" asked Holland, regaining his composure a little.

"We will assist you as best we can provided you treat us with like allies." Replied Optimus

"Deal. Well then, if you would kindly take me back via the route I was originally intended to take, we can sort all this out properly."

"Fine then, and thank you Colonel Holland, you may have just made the best decision for your race in a century." The Autobots transformed into their more discreet forms and continued on their route.

Jun was walking to the front of the outpost to secure colonel Holland's arrival and saw him arrive with a rather mismatched escort: a Mongoose, a Scorpion-class tank, a Pelican and something he had only ever heard about, a Gremlin. A special class of vehicle fitted with an EMP weapon. Holland exited the Warthog and all the soldiers stood at attention.

"At ease, everyone." Said Holland "I have something very important to show all of you, this is also why I called the other commanding officers here." As he said this, a convoy of official Warthogs drove up carrying important-looking people in them. As they assembled around Holland, a short man with a loud voice said "What is it Holland? I don't have all day."

"Don't worry Harper; you'll all be glad you came. But I must have all of you remain calm. Optimus, do your thing."

Behind Holland, the strange assortment of vehicles that made up his escort began to move of their own accord and grow to become huge humanoid robots. Cries of terror and surprise came up from around the crowd. Some officers tried backing away and the marines and Jun pointed their guns at them.

"Please stay calm! Stand down! They are our allies! To help us against the Covenant!" cried Holland

Most of the officers turned at his last exclamation. Several mutterings of:" They're here to help us?" and "Against the Covenant?"

The Autobots piped up

"I am Optimus Prime, leader of the Autobots-"

"The good guys." Interrupted Holland

"-and we have reason to believe that our mutual enemies the Decepticons are involved with the last Covenant attack on this planet. They may be gathering forces as we speak so time is of the essence."

"Just a minute," said someone from the back "why should we trust you? What if you're the same as these decepti-whatsits?"

"If they were, since we are all here, wouldn't they have killed us by now?" replied Holland, a little tired of the fact that it was hard to trust the Autobots at first.

"That's beside the point, though." Continued Holland "so how about we work together and see how it works out."

There was a general murmur of agreement throughout the assorted officials.

"Optimus, you said that the Covenant and the Decepticons are working together, what should we do about that then?" said Jun

"Knowing the Decepticons, they probably forced this Covenant you are fighting to help them return to full strength. If we can strike before that, we may be able to stop that from happening." Said Ratchet

"How are we going to attack them undetected? If they have access to Covenant technology, they can cloak themselves, or they could have those pylon things to mask their presence, or they could jam our sensors." Asked Harper, many nodded their heads in agreement.

"Don't worry, we'll find them, even if they hide underground, we'll find them." said Ironhide, pulling out a large 150mm cannon out.

"So, what do you want us to do exactly?" asked Holland

"If you can bring your heaviest and most manoeuvrable artillery that you can, it should be enough to pierce the Decepticon's shields and armour. We will assist, of course, and take the lead." said Optimus.

Holland turned to the marine with whom Jun had been doing the paperwork with previously and asked: "Marine, what heavy artillery do we have left?"

"Uh, let's see." The marine pulled out a data pad and scrolled down the screen.

"Apparently we have a Rhino still functioning, two Cobras, 9 Pelicans and three Wolverines."

"We should take all of them, even if the Cobras are slow, they can provide cover-fire from the cliffs." Interrupted Jun.

Holland turned to look at him.

"Sorry sir."

"No, that's true, you're the only one here who knows the terrain around the enemy, and you're going along on this little expedition, Spartan."


End file.
